Diagnosis
You want to assign a change package to a leading change master record.This is not possible because a new assignment to the leading changemaster record &V1& would cause an invaliddate shift in the changepackage.

System Response
The system checks whether a date shift changes the sequence of theeffectivity periof for an object (such as the sequence of severalchange statuses in a BOM item). Because of this the system blocks thisdate shift.

Procedure
Check in the object overview which objects you have changed in relationto the change package.
Display the objects.
Check the effectivity periods of the individual change statuses of theobjects.
Further informationen about date shifts can be found in the SAP Libraryin component Engineering Change Management (LO-ECH) underDate shift for das valid-from date.